Almost 75% of growth comes from growing far east markets as Dyson sales hit £3.5bn

Growing demand for battery-powered vacuum cleaners, hairdryers and air purifiers in flourishing Asian markets has helped Dyson, the British technology company, to a year of bumper profits.

Sir James Dyson, the British inventor who revolutionised the vacuum cleaner, said the company he founded had benefited from “extraordinary enthusiasm for technology” in Asia to help boost annual sales by 40% last year to reach £3.5bn.